Exploratory inference of the ingestive behavior of pigs in the growth phase in an air-conditioned environment

Abstract

The objective of this study was to carry out image monitoring and an exploratory analysis of abiotic factors, physiological responses and behavioral indicators of swine in the growth phase, subjected to supplementary lighting programs in air-conditioned environments. The animals were subjected to pens without air conditioning (PW), pens with forced ventilation (PV) and pens equipped with an adiabatic evaporative cooling system (PC), associated with different light supplementation programs: 12 h of natural light (L12), L12 + 4 h of artificial light (L16) and L12 + 6 h of artificial light (L18). Meteorological variables inside each pen and in external environment to the facilities, as well as physiological and behavioral parameters of the animals were recorded. The experimental design used was completely randomized, in a 3 × 3 factorial scheme, randomly distributed in nine pens, with three replicates. The data analysis used was multivariate, using the clustering method (tree diagram) and principal component analysis (PCA). The accumulated variance for PC1 and PC2 was greater than 69.70% for all treatments and the eigenvectors were greater than 2.68 according to the Kaiser criterion. The influence of the variables in relation to the ingestive behavior of the animals and consequently the regression models were established through PCA. Each treatment had a different regression model, so the variation factors influenced the ingestive behavior of the animals. The exploratory data analysis allowed establishing the influence of biotic and abiotic factors on the ingestive behavior of the animals. The regression models showed a coefficient of determination above 0.877 and a p-value below 0.05, ensuring that the models are reliable. The treatment with adiabatic evaporative cooling associated with 18 h of light showed the best fit models.